Mobtisina-chisel



` NITE STATES PATENT OFFICE. f

I. W. MCGAFFEY, OF PHILADELPHIA,PENNSYLVANIA.

MORTISING-CI-IISEL.

Specification of Letters Patent No. 10,421, dated January 10, 1854.

To all whom t may concern:

Be it known that I, I. W. MCGAFFEY, o-f the city and county of Philadelphia and State of Pennsylvania, have inventedanew and Improved Mortising-.Chiseh and `I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the accompanying drawings, making a part of this specilication, in which- Figure 1, is a perspective view of the chisel. Fig. 2, is a view showing the tongue of the chisel placed in the groove or recess of one of the lips. Fig. 3, is a transverse vertical section of the chisel, showing the lips closed. Fig. 4, is a view of the inner surface of one of the lips. Fig. 5, is a transverse vertical section of the chisel, showing the lips open and the tongue depressed.y

Similar letters of reference indicate corresponding parts in each of the several figures.

The mort-ising chisel to which this invention relates is designed to be used chiefly for mort-ising blind slats, and work of a like nature. It is to be applied to the mandrel or arbor of a mortising machine, and consists of a stock, having at its lower end a recess, in which are placed two cutting lips, having between them a tongue, which is depressed when the chisel is raised from the work. The cutting lips are so formed, as will be hereinafter shown, as to cut an aperture or mortise the required size at one operation and hold the chip or withdraw it from the mortise when the chisel is raised, the chip being forced from between the lips by the tongue, which, when it is depressed, forces apart the cutting edges of the lips, and drives out the chip, as will be hereinafter fully shown.

To enable those skilled in the art to make and use my invention, I will proceed to describe ts construction and operation.

A, represents the stock, the upper portion of which is cylindrical, and the lower portion-rectangular, as shown in Fig. 1. yIn the lower and rectangular portion of the stock is cut a vertical slot or recess, (a), in

. which are placed two cutting lips, B, B

The slot, (a), extends across the whole breadth of t-he stock, and the width of the cutting lips corresponds to the width of the lower portion of the stock. The lower parts of the lips have curved ends, (b), (b), so

that when the two lipsare together or the curved, ends of the two lips are in contact the cutting edges inclose a space correspondingk `to the slze of the required mortise.

This will be understood by reference to Fig. 1.

C, C, arepins, which pass through the "lower part of the stock, and through holes, (c), (c) in the cutting lips. The said holes, (c), c), in he cuttinglips, through which the plus pass, are -somewhat elliptical, as

lips to vibrate or play upon the pins. n

vThe inner surfaces or sides of the cutting lips have their upper parts,from points, (g), (g), just above the holes, (c), (c), to the top,-beveled or inclinedl graduallyy inward, as shown at (d), (d), in Figs. 3 and 5, a space being at the pointy (e), betwen the lips. The lower portions of t-he surfaces o-r sides of the lips are inclined or beveled in a reverse direction from the points, (f), (f), to the lower ends or cutting edges. Between the pome. (y), (y), and (f), (f). proie@- -t1ons, (i), are formed, and a vertical groove or recess, (j), is made through each projection, as seen in Figs. 2 and 4.

D, is a tongue, the lower part of which extendsv the widthA of the space inclosed by the two lips, B, B; see Figs. l, and 2. The upper paity Vof the tongue is curved gradually inward, forming a shank, (7c), which fits in the groove or recess, more particularly shown in Fig. 2. The shank, (7c), transversely, is of taperY form, as seen in Figs. 3 and 5. Atthe upper'part of the shank, (le), of the tongue, there is a crossbar E, of beveled form, as will be seen by the cross sections in Figs. 3 and 5. To the outer ends of the crossbar are attached arms, F, F, which extend upward by the side of the stock, A, as clearly shown in Fig. 1. The upper ends of the arms have a link, G, around them. Underneath the link, G, and around the stock, A, there is a spiral spring, H, seen in Figs. 1, 3, and 5, the upper end of the spring bearing against the under surface ,of the link, and the lower end against a shoulder, (l), at the upper part of the lower or rectangular portion of the stock.

I, is a gage point, attached to the stock, as shown in Figs. 3 and 5, the use of which gage point will be presently shown.

Operation The stock, A, is secured to the arbor or mandrel of a mortising machine; and when the chisel descends upon the work, the cutting edges of the lips peneshown in Figs. 2 and 4, in order to allow the trate thel wood, andcut a'chip theV desired sizeI ofthe mortise. When the chisel is withdrawn, the chip is retained within the lips and the niortise is formed. When the chisel has reached a certain height, the upper ends. of the arms, F, F, strike against a projection or stop, attachedfto thepinortisingv machine, and the arms F, F with Vthe' tongue, l), 'consequently will be stopped, and as the stock, A, rises, the tapershank, (7c), of the tongue bears againstthe points, (f), (f), on the inner surfaces of the cutting lips,and-forces the lower portions ofithe lips apart, `and the chip is thus forced out from between `the lips, as seen in Fig. 5, which'represents the tongue as being depressed and the lower por# tionsv of the lips spread apart.; chisel descends, the spiral spring, H, forces the tongueupward between the lips,l B, B, and the crossbar, E, `throws apart the upper portions of the lips, and the lower portions are consequently closed, and areready to4 Jform another mortise, asseen inl Fig. 3; The

lips, B, B, it vwill be' understood work v'upon the pins, C, C, as on fulcrums. `The gage,"l, each time the chisel descends, marks the spot on the work for the following Inortise.

The inner surfaces of the lips, just above VV-hen the V the cutting edges, may be serrated or creased,

similar to a le, if necessary,in order to insure the withdrawalof the chip from the mortise. A Y Having thus described my invention, what I claiin as new, and desire to secure by Letters-Patent, is

` Theconstruction 1of".thellzhisel substantially in the `manner herein shown and described; viz.,having`tw^o "cutting lips, B, B, insertedin a slot" or recess, (u), in the lower end of a stock, A"A, 'said lips working upon pins, G, C, which pass ythrough `the stock,

the inner surfaces ofthe lips being constructed as shown, andhaving a tongue, D, 1working between theIn,-which tongue, when Vthe chisel is raised, forces apart the cutting `edges of the lips, and throws out the chip from between the said lips; the crossbar,y E,

of the tongue, when the chisel descends, throwingapart the upper Vportions of the lips, and closing the lower Vand cutting ends; the tongue being raised between the lipsby ineans of the spring, H, or its equivalent.

I.V WV. MCGAFFEY.

Witnesses C. BRAZER, GEORGE D. vFREAS. 

